You don't have to use what "most people use" if what you're using is fully compatible, or at least compatible enough that it does everything you need it to do. PostgreSQL and MySQL are both SQL databases, so depending on what exactly you're doing, there's likely not that much difference in use. (Plus, these days, PostgreSQL seems to have become more popular.)
So if you're just editing text, it doesn't matter if most people are using emacs, because you can use vim too. But I guess for running an OS, FreeBSD has had too many pain points for many people compared to just going with the Linux crowd.
You would think so, but you'd be surprised what how people (mis)use stuff and how they enjoy using vendor specific features / extensions. This is also, imo, what kind of killed the adoption of J2EE and even J2ME. I'm not talking about J2EE/JEE + Spring*, or using an embedded tomcat. I'm talking about basically what everybody's trying to create for the last 20 years in terms of deployment etc. Sun had it pretty much figured out back then
For editing text, I only use vi.. It's available everywhere and I know my way around it.
I'm glad postgres became popular :). The reasoning around using what many people use is that software is generally more available..
Maybe I'll give FreeBSD another swing in the future, but I'm not sure what the state of containers is. I used jails back in the days, but I'll have to do some research on that.
So if you're just editing text, it doesn't matter if most people are using emacs, because you can use vim too. But I guess for running an OS, FreeBSD has had too many pain points for many people compared to just going with the Linux crowd.